ATPL Performance and Loading

[brns2]

Just starting to study for the P and L exam, wondering if anyone has any tips?

Im currently using the Aviation Theory Center Aeroplane performance,planning and loadingn for the ATPL. It is referencing 737 performance charts. I thought we would be tested on the 727 p charts in the blue 727 handbook?

Also the back of the Aviation Theory center book has a 727 weight and balance booklet. All the numbers are slightly different from the blue 727 hanbook?

The ASL site says the 727 performance and operating handbook is to be brought to the exam. will we be using the p charts out of this? There is no weight and balance chart tho?

Do ASL give you any booklets/charts in the exam? if so what kind of things do they contain?

Thanks in advance for your help!

[PLovett]

Do ASL give you any booklets/charts in the exam? if so what kind of things do they contain?

Yep, and a "fingernail dipped in tar" could have drawn a better chart. The provided material is bleedin awful. The figures between the B727 POH and the W & B booklet are slightly different but the figures from the POH can be used.

The booklet provided actually has more stuff in it than you need. I suspect it was meant to cover more exams than just the P & L.

Tips, get a pair of dividers, a clear plastic ruler and something like a red biro with a fine tip. The dividers are very useful for measuring load changes from one sector to another, the clear plastic ruler for drawing accurate parallel lines on the load sheet and the red biro to draw lines that can be easily distinguished from the dark lines on the sh*te charts they provide.

Good luck.

[FRQ Charlie Bravo]

Hey brns2 (and anybody else in the same boat),

I'm at the begining of studying for P and L too. PM if you want to go over anything.

FRQ CB

PS I checked on some dividers at the local drawing supply store and they are about $45. Will let you know if I find anything better.

[Di_Vosh]

BRNS2

I think you've outlined your problem when you said:

Im currently using the Aviation Theory Center Aeroplane performance,planning and loadingn for the ATPL. It is referencing 737 performance charts. I thought we would be tested on the 727 p charts in the blue 727 handbook?


Get the info from Nathan Higgins at AFT! Esp. if you're self-studying :ok:

I self-studied 5 of the 7 ATPL subjects, and found that Nathans notes were in a league of their own. Trevor Thom and Aviation Theory Center notes were nowhere near as good.

DIVOSH!

[ryda]

In the exam, you get a 727 weight and balance book and 5 pages of 727 load/ trim sheet. You will get around 2 questions worth 4 marks each that require you to complete the trim sheet in full. The answers are really close together so complete accuracy is necessary. For my exam I got: Find stabilizer setting for 15 degree flap. The answers to pick were A)5.3 B)5.1 C)4.9 D)4.7 E)4.3

As you can see they are extremely close, and I got 5.0 which is right in the middle of two answers. Took a guess and got it wrong even though I checked everything thoroughly.

Use the numbers provided by the Weight and Balance Booklet. I got some cheap dividers from my local newsagent for $3. I would use a 0.3mm mechanical pencil instead of pens or pencils.

They also provide charts for Take off and Landing so you don't mess up your blue book. I got 1 question on each and are worth 3 marks each.

The AFT notes are excellent and should get you through the exam comfortably.

[john_tullamarine]

The answers to pick were A)5.3 B)5.1 C)4.9 D)4.7 E)4.3

Utter pedantic nonsense ...

[PLovett]

Utter pedantic nonsense ...

But john, isn't that the case with all the ATPL exams with the possible exception of Systems?

The whole thing appears to be an exercise in theory for the sake of theory with no real application in the real world.

[rammel]

Agree with the comment about it being pedantic. Your answer could be a or b, b or c, or c or d, depending on where your line is. The only way it would be e is if the line was the closet to 4. Haven't seen the B727 trim chart, but if it is the one where you draw the lines and then drop it down, they are very much open to variations. The majority of QF trim charts are now the fill in the box type, then you plot it on the chart.

[likes2fly]

I found it handy if you get answers which are close together, reverse engineer the question, once you think you are close. I.e. start at the stab trim setting for the answers you are conflicting with and work your way back up looking for possible errors.

You need to be REALLY careful with the c of g corrections for each zone as even the slightest error can put you into the next answer zone, so frustrating.

Also once you get to the fuel reference table, the charts i was provided with weren't always perfectly straight, parallel lines, again causing errors.

Get the finest pacer pencil you can, as even .1mm X 10 lines could put you in the next answer region.

I used Rob Avery's correspondance course, although pretty ancient material, it covered everything. AFT's cyberexams seem to be pretty spot on though, and good prep for the actual exam.

All the best,

[AerocatS2A]

I found the trim answers to be different enough so that my answer wasn't ambiguous. If you want accurate parallel lines use a couple of set squares.

[Wing Root]

Isn't it fascinating that the bloke who actually MADE the W&B chart calls the accuracy required in the exam "Utter pedantic nonsense." Just more proof these exams have little relevance in the real word. :ugh:

[ReverseFlight]

I self-studied by Rob Avery's textbook without his correspondence course and still passed comfortably. Proves it can be done.

I found P&L quite interesting. Make sure you work through all his examples and exercises. All the best with your exams.

[john_tullamarine]

But john, isn't that the case with all the ATPL exams with the possible exception of Systems?

Although I am quite out of touch with the exams these days, in a previous life I taught most of the exam subjects for some years.

Philosophically, I do not incline to the view that exams ought to be "practical" as the practical bits are more appropriately assessed in the sim and the aircraft. The exams ought to have an emphasis on the underlying subject matter. However, they ought to have an appropriate relevance both to the subject matter and the end aim .. which is to produce competent aircrew.

My concern is not that accuracy is required but that the emphasis is inappropriate -

(a) the (in)accuracy of the empty weight data does not just justify such superhuman effort on the part of the person completing the sheet. Accuracy is a good thing and you MUST use a suitable straight edge to complete the sheet. For the exams, probably a Douglas protractor is the way to go. As an aside, it was always my understanding that trimsheet completion was the initial reason for the introduction of ID cards ? ... it was rumoured that even "Nigger" up at the AN freight shed at SYD could run an half decent trimsheet with his ID although he had some difficulty holding the pencil appropriately ... A significant concern is that the student is left with a misconceived idea of the accuracy of weight and balance if this sort of thing is required in exams. The "closeness" of the answers ought to be of sufficient degree to match a "reasonable" completion of a trimsheet but not excessively more than this.

(b) such a fine level of answer discrimination does not contribute to basic understanding or competence

(c) there are more useful trimsheet exercises which could be incorporated into the exams for training/assessment value than a mere emphasis on drafting capability

(d) in general, a trim sheet has inbuilt simplifying errors (which are accounted for in the design error analysis). The end result is that the calculated CG incorporates an error which means that the stab trim read off is only approximate at best

(e) the stab trim is not so critical that it matters all that much whether there is a modest error in the cockpit setting.

Isn't it fascinating that the bloke who actually MADE the W&B chart

Not guilty although I have designed the odd Boeing sheet over the years. Without checking what is being used, I can only hazard a guess that the trimsheet will be one of the the old AN or TN sheets with some of the extraneous graphical detail removed. Very possibly it is the sheet which was in the old DCA weight control blue book. Scratching the memory (as I haven't seen a copy of that for some time) I think that sheet was a TN variant.

At the end of the day, though, please spare a thought for the poor old examiner. They have a difficult job and whichever way they go some sections of the Industry will gripe and complain .. damned if they do and damned if they don't, I guess.

[PLovett]

John, thank you for your thoughts on the matter.

Like one of the other posters, I found the level of accuracy required in drafting on the weight and balance charts to be very high, especially given that the loads for the various load sectors often required interpolation. If there was any divergence in your lines from either the vertical or in drawing the final line to the trim setting, especially the latter, then it was very easy to get the answer wrong. This was compounded by the extremely poor quality charts provided, especially the landing and takeoff distance charts where many supposedly parallel lines were not.

As an aside, I found the questions in the P & L exam to be reasonably straight forward unlike Flight Planning which so often appeared to be designed to trick you, e.g. giving a ramp weight instead of brakes release weight.

If the intention is to test underlying knowledge then I believe there are better ways to do this than the present system.

[john_tullamarine]

Some thoughts ..

(a) especially given that the loads for the various load sectors often required interpolation

It is fairly easy to avoid problems with the droplines .. keep in mind that trimsheets have vertical IU scale lines precisely to assist. Using something like a Douglas protractor makes the problem go away so long as a modicum of care is employed. The greater problem is that of trimline tick interpolation .. which is why many trimsheets use the slopey line drafting trick to reduce two interpolations to one.

(b) This was compounded by the extremely poor quality charts provided

Not having seen the actual charts, I can't comment but, if you are of such a view, then you might consider writing an appropriate note to the senior examiner .. unfortunately, having been out of that arena for many years, I have no contacts to offer.

(c) unlike Flight Planning which so often appeared to be designed to trick you, e.g. giving a ramp weight instead of brakes release weight.

Yes and no. One of the system's underlying aims is to use all reasonable means to assess cognitive suitability to the job. Aspects of exams (and flight tests, for that matter) which may appear, on the surface, to be motivated by a desire to deceive or mislead are, in fact, fairly standard techniques to assess the applicant's general alertness and attention to detail .. ie the old RTFQ advice ... As trivial examples, how many times does the ATO/check captain engage the testee in distracting discussion with 200 foot to go to altitude/20 degrees to go to the lead radial, etc, etc .. ?

Unfortunately, in the aviation game, all are not equal in talent and capability (hence the need for directed training to get the message across). Indeed, a small group is just not suited to the task ... having said that, I've managed to get through with only having to scrub a total of two ...

(d) then I believe there are better ways to do this

.. ah .. line up a hundred and ask the question .. and you are likely to get two hundred answers .. the age old problem.

[FRQ Charlie Bravo]

Hey Ryda,

The cheap dividers you bought, were they a set of 10 points (when I was in the military we called them 10 points but they have 11 pointy tips which, when the first point is placed on an origin, will give the next ten multiples) or just a compass-style (http://en.wikipedia.org/wiki/Compass_%28drafting%29) set (two pointy tips)?

i.e.
http://ec1.images-amazon.com/images/I/51v9g42vsmL._AA280_.jpg

or

http://www.theartistsdepot.com/images/Site_Ready/Thumbs/tn_jetbow_divider.jpg?

The ten points would be perfect for uber-accurate readings on the B727 Initial Buffet Boundaries chart (not required as eyeballing it should be of sufficient accuracy).

~FRQ CB

[ksa5223]

thats some flash equipment! I searched high and low for high quality dividers, if anyone finds any ie. staedler or something online post the link!

Tips would be practice exams and know the weight and balance booklet back to front (i got 95% with secombe notes) I found it pretty simple to study it, also know your aircraft speed definitions.

[ryda]

Wow first time i've seen that 10 points thing.

Yeah i got a 2 point one but didn't really need it for the exam.

I got many questions about V1, VR, V2 speeds etc

[FRQ Charlie Bravo]

I was a sonar tech in Orions and during training we used the ten points to find harmonics of sounds made my submarines. All done on computers in the fleet (real world) but I suppose that "back in the day" you would have seen aircrew carrying these things onto the aircraft.

I reckon I'll just stick with the two point type or even just a compass (divider with one point and one pencil).

Off to the library to study now.

FRQ CB

[FRQ Charlie Bravo]

Refer to the B727 POH graph 2.1 page 2-5. Imagine drawing a line all the way around from EOL through all the steps and when you get to the OAT Ref Line ending up at the same place as the example (15 deg C and 74t). To continue to your OAT of (and I'm diverging from the example now) 40 deg C you've got to line up your ruler with the "walk" line (apparently this is the name of the lines you follow from a reference line) and carefully slide it down to be able to continue drawing your line all the while trying to maintain the same angle as the walk line.

With regards to useful gadgets: as I was doing some take-off charts the other day it dawned on me that the perfect (and simple) tool for the job would be a set of parallel rulers.
http://boatsafe.com/navigation/rulemoov2.gif

Useful as a straight edge and normal ruler but for when you've got to go from a reference line out to a point between two "walk" lines you could simply line the parallel ruler up on the nearest "walk" line to set up the correct angle relative to the rest of the graph and then move the second half of the ruler to intercept and continue your drawing from the reference line. If the walk lines between which you must draw are too different from each other you could just draw two lines and split the difference visually.

This sounds very complicated but if you are remotely familiar with the problem I'm writing about then it shouldn't be.

On the other hand if you have two nice accurate rulers (or a ruler and a straight edge protractor) with accurate 90 degree edges you could just line the first up with the walk line, firmly abut (place against) the second to it and then using this second straight edge as a guide slide the first down to intercept and continue your drawing line.

On another matter altogether:

Looking at my RDS I'm tempted to highlight the appropriate (shortest relevant) TODA/ASDA/STODA. Would this be of benefit in the exam or have I not thought it through well enough (could this lead me astray with another type of Q)?

Is time as much of an issue as it was with FPL or the IREX?

Anybody from Perth sitting this soon?

~FRQ CB

[ryda]

Time was not an issue for me but then again time wasn't an issue for me in any of the exams. I just used a regular ruler and it worked out fine. You don't need to be too accurate. I only got 1 question on this in the exam. The question actually gives you the distances on screen so you may highlight the screen if you wish. :}

[brns2]

hey FCB,

How so you post pictures up??

I have a couple of graphs id like to post and ask some questions about

[FRQ Charlie Bravo]

hey FCB,

How do you post pictures up??

I have a couple of graphs id like to post and ask some questions about


It's pretty straight forward:

If the image is already somewhere on the internet just open it in another page (another tab usually doesn't work) then click, drag and drop into your text.
If the image is not anywhere on the Internet then you've got to put it somewhere. Just get a free account at photobucket.com and scan it (or if no scanner then take a photo with your camera), upload it and then click, drag and drop (as above) from that website.Technically I don't think that I'm supposed to post other people's work into a forum without giving the author credit but I didn't think that the lovely folks ;) at theartistdepot.com (http://www.pprune.org/theartistdepot.com), amazon.com (http://www.pprune.org/amazon.com) or boatsafe.com (http://www.pprune.org/boatsafe.com) would have really cared. (OK authors, consider yourselves credited). Happy plagiarising:ok:,

FRQ CB

[brns2]

http://i463.photobucket.com/albums/qq355/brns2/1.jpg

Thanks FCB for that.

Im having a problem comparing these 2 graphs

The above is suggesting that Vimd is also max range speed. I thought max range is 1.32Vimd.

Where as the below is suggesting Vimd is best endurance speed (which i believe is correct)

What do you think?



http://i463.photobucket.com/albums/qq355/brns2/Untitled.jpg

[PLovett]

I might be misunderstanding your problem, I often do :} but best endurance and best range are two different things.

Best endurance = Vimd
Best range = 1.32 x Vimd

The top image is misleading because of the vertical line connecting the two graphs. However, it is correct because the two graphs show different things. The top image is graphing thrust or drag and the second image is graphing power. Hence the confusion.

[brns2]

PLovett yeh i agree with you.

I realise the lower graph in the top picture is showing power reqd

But as you say i am confused with the top picture. because its suggesting the Vimd (top graph) is also max range speed(bottom graph). Which isnt true

With the top picture. Shouldnt Vimd (top graph) line up with best endurance(bottom graph)?

[defiant]

This may help re vimd question...

http://www.pprune.org/tech-log/267271-vimd.html

See post by Oktas8 at the bottom.

It appears Vimd is approximately the best range cruise speed for a piston engine aircraft, and approximately the best endurance speed for a turbo jet aircraft.

May explain the discrepancy in graphs, one may be for piston other for jets.

[ksa5223]

V1 Decision speed – speed to determine whether to continue or abort the takeoff following a failure of the critical engine. Failure below V1 is an abort, at or above V1 the takeoff is continued.

VMCG – minimum control speed – ground – min speed directional control using primary aerodynamic controls following failure of critical engine with max thrust set in take off config.

VMCA – Minimum control speed – air – min speed a/c can be kept within specified limits of heading and attitude following failure of critical engine in second segment config with t/o thrust applied. Defined with a rearmost CoG, within limits which gives highest value of VMCA.

VR - Speed which rotation is initiated by pilot to achieve V2 at or below 35’ with 1 engine inoperative.
VS – minimum steady flight speed / minimum speed in a stall.
VLO – speed a/c lifts off the ground.

VMIN UNSTICK – min speed a/c will lift off gnd. Done doing testing, over rotated early in take off roll, tail strike normally, held nose high attitude until lift off.

V2 – TOSS – following correct rotation and lift off procedures, allows a/c maintain gradient in climb out. Achieve by 35’.
VREF – Reference speed is the landing speed in a nominated configuration, eg VREF 30 would be the landing speed with flaps at 30°.
VMCG ≤ V1 ≤ VR
VR≥ V1 and 1.05VMCA
V2 ≥ 1.1 x VMCA and 1.2 x VS
VR – such that rotation 10kts below VR will not increase the TODR

[blumoon]

When i did the W&B graphs i, (and class mates), worked out a different way.

Instead of trying to find the thinnest pencil imaginable with the straightest ruler we used the following procedure:

1. At the start of the exam (or even in the 'pre-reading' time) work out how many 'mm' 'millimeters' each passenger in each section is worth. Do this by measuring say 50 passengers length and divide by 50. eg. You may end up with each passenger in 'ROWS 23-27' section is equal to 1.2mm.

2. For the actual question you need a baseline to start from. Draw a vertical line from the 'BASIC INDEX' amount. Your final calculation will be measured from this.

3. Then simply work through all the distances for each load segment. ENSURE you use a + or - depending on whether that section moves the index forward or aft (doesn't really matter which is -ive or +ive but it needs to be consistent).

4. Then just add it all up: For example you may have : + 5mm (ROW 1-6), + 3.2mm (ROW 7-12), +4.5mm (ROW 13-17), - 3.2mm (ROW 18-22) etc etc etc. You will end up with a measurement of say 23.8mm.

5. Then just measure the 23.8 mm in the '+ive' direction from you initial 'INDEX line' along the bottom of the graph (fuel area).

This way you only need to actually use the ruler for a couple of lines instead of mucking around with all the various measurements for each row. (and going cross-eyed:8) And the great thing about this method is if in later questions you get the 'What's the change when moving 5 pax from ROWs 7-12 to ROWs 23-27' is you just need to make a basic summation of ' -(5 x ?? mm) + (5 x ??mm) and move your baseline that amount.:ok:

It's been a while since i looked at that exam but it gave just about everyone BIG marks...

Worked for us!:E

[brns2]

can anyone confirm that you do get an electronic calculator provided by asl?

thanks

[PLovett]

brns2,

Yep, ASL provide one, however, some have seen better days so if you have one of the same type it is worth taking it with you just in case.

I was also given some advice that when you sit down at the desk, test the calculator provided. Enter a line of "8" so that you can see if any of the elements are broken, then do a couple of simple calculations just to see that the thing is working. If you have read the thread on flight planning you will know that some people have had less than ideal calculators to work with.:ok: